## What changes were proposed in this pull request?
These 3 methods have to be used together, so it makes more sense to merge them into one method and then the caller side only need to call one method.
## How was this patch tested?
existing tests.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18579 from cloud-fan/minor.
## What changes were proposed in this pull request?
Since we do not set active sessions when parsing the plan, we are unable to correctly use SQLConf.get to find the correct active session. Since https://github.com/apache/spark/pull/18531 breaks the build, I plan to revert it at first.
## How was this patch tested?
The existing test cases
Author: Xiao Li <gatorsmile@gmail.com>
Closes#18568 from gatorsmile/revert18531.
## What changes were proposed in this pull request?
This pr modified code to use string types by default if `array` and `map` in functions have no argument. This behaviour is the same with Hive one;
```
hive> CREATE TEMPORARY TABLE t1 AS SELECT map();
hive> DESCRIBE t1;
_c0 map<string,string>
hive> CREATE TEMPORARY TABLE t2 AS SELECT array();
hive> DESCRIBE t2;
_c0 array<string>
```
## How was this patch tested?
Added tests in `DataFrameFunctionsSuite`.
Author: Takeshi Yamamuro <yamamuro@apache.org>
Closes#18516 from maropu/SPARK-21281.
## What changes were proposed in this pull request?
un-aliased subquery is supported by Spark SQL for a long time. Its semantic was not well defined and had confusing behaviors, and it's not a standard SQL syntax, so we disallowed it in https://issues.apache.org/jira/browse/SPARK-20690 .
However, this is a breaking change, and we do have existing queries using un-aliased subquery. We should add the support back and fix its semantic.
This PR fixes the un-aliased subquery by assigning a default alias name.
After this PR, there is no syntax change from branch 2.2 to master, but we invalid a weird use case:
`SELECT v.i from (SELECT i FROM v)`. Now this query will throw analysis exception because users should not be able to use the qualifier inside a subquery.
## How was this patch tested?
new regression test
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18559 from cloud-fan/sub-query.
## What changes were proposed in this pull request?
Rename org.apache.spark.sql.catalyst.plans.logical.statsEstimation.Range to ValueInterval.
The current naming is identical to logical operator "range".
Refactoring it to ValueInterval is more accurate.
## How was this patch tested?
unit test
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Wang Gengliang <ltnwgl@gmail.com>
Closes#18549 from gengliangwang/ValueInterval.
## What changes were proposed in this pull request?
Currently we can't produce a `Dataset` containing `Set` in SparkSQL. This PR tries to support serialization/deserialization of `Set`.
Because there's no corresponding internal data type in SparkSQL for a `Set`, the most proper choice for serializing a set should be an array.
## How was this patch tested?
Added unit tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#18416 from viirya/SPARK-21204.
## What changes were proposed in this pull request?
When data type is struct, InSet now uses TypeUtils.getInterpretedOrdering (similar to EqualTo) to build a TreeSet. In other cases it will use a HashSet as before (which should be faster). Similarly, In.eval uses Ordering.equiv instead of equals.
## How was this patch tested?
New test in SQLQuerySuite.
Author: Bogdan Raducanu <bogdan@databricks.com>
Closes#18455 from bogdanrdc/SPARK-21228.
## What changes were proposed in this pull request?
Add missing test cases back and revise code style
Follow up the previous PR: https://github.com/apache/spark/pull/18479
## How was this patch tested?
Unit test
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Wang Gengliang <ltnwgl@gmail.com>
Closes#18548 from gengliangwang/stat_propagation_revise.
## What changes were proposed in this pull request?
Corrects offsetInBytes calculation in UnsafeRow.writeToStream. Known failures include writes to some DataSources that have own SparkPlan implementations and cause EXCHANGE in writes.
## How was this patch tested?
Extended UnsafeRowSuite.writeToStream to include an UnsafeRow over byte array having non-zero offset.
Author: Sumedh Wale <swale@snappydata.io>
Closes#18535 from sumwale/SPARK-21312.
### What changes were proposed in this pull request?
This PR removes SQLConf parameters from the optimizer rules
### How was this patch tested?
The existing test cases
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18533 from gatorsmile/rmSQLConfOptimizer.
### What changes were proposed in this pull request?
This PR is to remove SQLConf parameters from the parser-related classes.
### How was this patch tested?
The existing test cases.
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18531 from gatorsmile/rmSQLConfParser.
## What changes were proposed in this pull request?
support to create [temporary] function with the keyword 'OR REPLACE' and 'IF NOT EXISTS'
## How was this patch tested?
manual test and added test cases
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: ouyangxiaochen <ou.yangxiaochen@zte.com.cn>
Closes#17681 from ouyangxiaochen/spark-419.
## What changes were proposed in this pull request?
Currently `RowEncoder` doesn't preserve nullability of `ArrayType` or `MapType`.
It returns always `containsNull = true` for `ArrayType`, `valueContainsNull = true` for `MapType` and also the nullability of itself is always `true`.
This pr fixes the nullability of them.
## How was this patch tested?
Add tests to check if `RowEncoder` preserves array/map nullability.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#13873 from ueshin/issues/SPARK-16167.
## What changes were proposed in this pull request?
Add `returnNullable` to `StaticInvoke` the same as #15780 is trying to add to `Invoke` and modify to handle properly.
## How was this patch tested?
Existing tests.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#16056 from ueshin/issues/SPARK-18623.
## What changes were proposed in this pull request?
For these collection-related encoder expressions, we don't need to create `isNull` variable if the loop element is not nullable.
## How was this patch tested?
existing tests.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18529 from cloud-fan/minor.
## What changes were proposed in this pull request?
`ExternalMapToCatalyst` should null-check map key prior to converting to internal value to throw an appropriate Exception instead of something like NPE.
## How was this patch tested?
Added a test and existing tests.
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#18524 from ueshin/issues/SPARK-21300.
### What changes were proposed in this pull request?
It is strange to see the following error message. Actually, the column is from another table.
```
cannot resolve '`right.a`' given input columns: [a, c, d];
```
After the PR, the error message looks like
```
cannot resolve '`right.a`' given input columns: [left.a, right.c, right.d];
```
### How was this patch tested?
Added a test case
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18520 from gatorsmile/removeSQLConf.
### What changes were proposed in this pull request?
SQLConf is moved to Catalyst. We are adding more and more test cases for verifying the conf-specific behaviors. It is nice to add a helper function to simplify the test cases.
### How was this patch tested?
N/A
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18469 from gatorsmile/withSQLConf.
## What changes were proposed in this pull request?
Looking at the code in `SessionCatalog.registerFunction`, the parameter `ignoreIfExists` is a wrong name. When `ignoreIfExists` is true, we will override the function if it already exists. So `overrideIfExists` should be the corrected name.
## How was this patch tested?
N/A
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18510 from cloud-fan/minor.
### Idea
This PR adds validation to REFRESH sql statements. Currently, users can specify whatever they want as resource path. For example, spark.sql("REFRESH ! $ !") will be executed without any exceptions.
### Implementation
I am not sure that my current implementation is the most optimal, so any feedback is appreciated. My first idea was to make the grammar as strict as possible. Unfortunately, there were some problems. I tried the approach below:
SqlBase.g4
```
...
| REFRESH TABLE tableIdentifier #refreshTable
| REFRESH resourcePath #refreshResource
...
resourcePath
: STRING
| (IDENTIFIER | number | nonReserved | '/' | '-')+ // other symbols can be added if needed
;
```
It is not flexible enough and requires to explicitly mention all possible symbols. Therefore, I came up with the current approach that is implemented in the code.
Let me know your opinion on which one is better.
Author: aokolnychyi <anton.okolnychyi@sap.com>
Closes#18368 from aokolnychyi/spark-21102.
## What changes were proposed in this pull request?
We currently implement statistics propagation directly in logical plan. Given we already have two different implementations, it'd make sense to actually decouple the two and add stats propagation using mixin. This would reduce the coupling between logical plan and statistics handling.
This can also be a powerful pattern in the future to add additional properties (e.g. constraints).
## How was this patch tested?
Should be covered by existing test cases.
Author: Reynold Xin <rxin@databricks.com>
Closes#18479 from rxin/stats-trait.
## What changes were proposed in this pull request?
Update stats after the following data changing commands:
- InsertIntoHadoopFsRelationCommand
- InsertIntoHiveTable
- LoadDataCommand
- TruncateTableCommand
- AlterTableSetLocationCommand
- AlterTableDropPartitionCommand
## How was this patch tested?
Added new test cases.
Author: wangzhenhua <wangzhenhua@huawei.com>
Author: Zhenhua Wang <wzh_zju@163.com>
Closes#18334 from wzhfy/changeStatsForOperation.
## What changes were proposed in this pull request?
For performance reasons, `UnsafeRow.getString`, `getStruct`, etc. return a "pointer" that points to a memory region of this unsafe row. This makes the unsafe projection a little dangerous, because all of its output rows share one instance.
When we implement SQL operators, we should be careful to not cache the input rows because they may be produced by unsafe projection from child operator and thus its content may change overtime.
However, when we updating values of InternalRow(e.g. in mutable projection and safe projection), we only copy UTF8String, we should also copy InternalRow, ArrayData and MapData. This PR fixes this, and also fixes the copy of vairous InternalRow, ArrayData and MapData implementations.
## How was this patch tested?
new regression tests
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18483 from cloud-fan/fix-copy.
### What changes were proposed in this pull request?
Function argument should not be named expressions. It could cause two issues:
- Misleading error message
- Unexpected query results when the column name is `distinct`, which is not a reserved word in our parser.
```
spark-sql> select count(distinct c1, distinct c2) from t1;
Error in query: cannot resolve '`distinct`' given input columns: [c1, c2]; line 1 pos 26;
'Project [unresolvedalias('count(c1#30, 'distinct), None)]
+- SubqueryAlias t1
+- CatalogRelation `default`.`t1`, org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe, [c1#30, c2#31]
```
After the fix, the error message becomes
```
spark-sql> select count(distinct c1, distinct c2) from t1;
Error in query:
extraneous input 'c2' expecting {')', ',', '.', '[', 'OR', 'AND', 'IN', NOT, 'BETWEEN', 'LIKE', RLIKE, 'IS', EQ, '<=>', '<>', '!=', '<', LTE, '>', GTE, '+', '-', '*', '/', '%', 'DIV', '&', '|', '||', '^'}(line 1, pos 35)
== SQL ==
select count(distinct c1, distinct c2) from t1
-----------------------------------^^^
```
### How was this patch tested?
Added a test case to parser suite.
Author: Xiao Li <gatorsmile@gmail.com>
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18338 from gatorsmile/parserDistinctAggFunc.
## What changes were proposed in this pull request?
Invalidate spark's stats after data changing commands:
- InsertIntoHadoopFsRelationCommand
- InsertIntoHiveTable
- LoadDataCommand
- TruncateTableCommand
- AlterTableSetLocationCommand
- AlterTableDropPartitionCommand
## How was this patch tested?
Added test cases.
Author: wangzhenhua <wangzhenhua@huawei.com>
Closes#18449 from wzhfy/removeStats.
## What changes were proposed in this pull request?
`QueryPlan.preCanonicalized` is only overridden in a few places, and it does introduce an extra concept to `QueryPlan` which may confuse people.
This PR removes it and override `canonicalized` in these places
## How was this patch tested?
existing tests
Author: Wenchen Fan <wenchen@databricks.com>
Closes#18440 from cloud-fan/minor.
## What changes were proposed in this pull request?
Move elimination of Distinct clause from analyzer to optimizer
Distinct clause is useless after MAX/MIN clause. For example,
"Select MAX(distinct a) FROM src from"
is equivalent of
"Select MAX(a) FROM src from"
However, this optimization is implemented in analyzer. It should be in optimizer.
## How was this patch tested?
Unit test
gatorsmile cloud-fan
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Wang Gengliang <ltnwgl@gmail.com>
Closes#18429 from gengliangwang/distinct_opt.
## What changes were proposed in this pull request?
The issue happens in `ExternalMapToCatalyst`. For example, the following codes create `ExternalMapToCatalyst` to convert Scala Map to catalyst map format.
val data = Seq.tabulate(10)(i => NestedData(1, Map("key" -> InnerData("name", i + 100))))
val ds = spark.createDataset(data)
The `valueConverter` in `ExternalMapToCatalyst` looks like:
if (isnull(lambdavariable(ExternalMapToCatalyst_value52, ExternalMapToCatalyst_value_isNull52, ObjectType(class org.apache.spark.sql.InnerData), true))) null else named_struct(name, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, assertnotnull(lambdavariable(ExternalMapToCatalyst_value52, ExternalMapToCatalyst_value_isNull52, ObjectType(class org.apache.spark.sql.InnerData), true)).name, true), value, assertnotnull(lambdavariable(ExternalMapToCatalyst_value52, ExternalMapToCatalyst_value_isNull52, ObjectType(class org.apache.spark.sql.InnerData), true)).value)
There is a `CreateNamedStruct` expression (`named_struct`) to create a row of `InnerData.name` and `InnerData.value` that are referred by `ExternalMapToCatalyst_value52`.
Because `ExternalMapToCatalyst_value52` are local variable, when `CreateNamedStruct` splits expressions to individual functions, the local variable can't be accessed anymore.
## How was this patch tested?
Jenkins tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#18418 from viirya/SPARK-19104.
## What changes were proposed in this pull request?
Time windowing in Spark currently performs an Expand + Filter, because there is no way to guarantee the amount of windows a timestamp will fall in, in the general case. However, for tumbling windows, a record is guaranteed to fall into a single bucket. In this case, doubling the number of records with Expand is wasteful, and can be improved by using a simple Projection instead.
Benchmarks show that we get an order of magnitude performance improvement after this patch.
## How was this patch tested?
Existing unit tests. Benchmarked using the following code:
```scala
import org.apache.spark.sql.functions._
spark.time {
spark.range(numRecords)
.select(from_unixtime((current_timestamp().cast("long") * 1000 + 'id / 1000) / 1000) as 'time)
.select(window('time, "10 seconds"))
.count()
}
```
Setup:
- 1 c3.2xlarge worker (8 cores)
1 B rows ran in 287 seconds after this optimization. I didn't wait for it to finish without the optimization. Shows about 5x improvement for large number of records.
Author: Burak Yavuz <brkyvz@gmail.com>
Closes#18364 from brkyvz/opt-tumble.
### What changes were proposed in this pull request?
```SQL
CREATE TABLE `tab1`
(`custom_fields` ARRAY<STRUCT<`id`: BIGINT, `value`: STRING>>)
USING parquet
INSERT INTO `tab1`
SELECT ARRAY(named_struct('id', 1, 'value', 'a'), named_struct('id', 2, 'value', 'b'))
SELECT custom_fields.id, custom_fields.value FROM tab1
```
The above query always return the last struct of the array, because the rule `SimplifyCasts` incorrectly rewrites the query. The underlying cause is we always use the same `GenericInternalRow` object when doing the cast.
### How was this patch tested?
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18412 from gatorsmile/castStruct.
## What changes were proposed in this pull request?
`isTableSample` and `isGenerated ` were introduced for SQL Generation respectively by https://github.com/apache/spark/pull/11148 and https://github.com/apache/spark/pull/11050
Since SQL Generation is removed, we do not need to keep `isTableSample`.
## How was this patch tested?
The existing test cases
Author: Xiao Li <gatorsmile@gmail.com>
Closes#18379 from gatorsmile/CleanSample.
## What changes were proposed in this pull request?
Currently we do a lot of validations for subquery in the Analyzer. We should move them to CheckAnalysis which is the framework to catch and report Analysis errors. This was mentioned as a review comment in SPARK-18874.
## How was this patch tested?
Exists tests + A few tests added to SQLQueryTestSuite.
Author: Dilip Biswal <dbiswal@us.ibm.com>
Closes#17713 from dilipbiswal/subquery_checkanalysis.
## What changes were proposed in this pull request?
If the SQL conf for StateStore provider class is changed between restarts (i.e. query started with providerClass1 and attempted to restart using providerClass2), then the query will fail in a unpredictable way as files saved by one provider class cannot be used by the newer one.
Ideally, the provider class used to start the query should be used to restart the query, and the configuration in the session where it is being restarted should be ignored.
This PR saves the provider class config to OffsetSeqLog, in the same way # shuffle partitions is saved and recovered.
## How was this patch tested?
new unit tests
Author: Tathagata Das <tathagata.das1565@gmail.com>
Closes#18402 from tdas/SPARK-21192.
## What changes were proposed in this pull request?
After wiring `SQLConf` in logical plan ([PR 18299](https://github.com/apache/spark/pull/18299)), we can remove the need of passing `conf` into `def stats` and `def computeStats`.
## How was this patch tested?
Covered by existing tests, plus some modified existing tests.
Author: wangzhenhua <wangzhenhua@huawei.com>
Author: Zhenhua Wang <wzh_zju@163.com>
Closes#18391 from wzhfy/removeConf.
## What changes were proposed in this pull request?
The current master outputs unexpected results when the data schema and partition schema have the duplicate columns:
```
withTempPath { dir =>
val basePath = dir.getCanonicalPath
spark.range(0, 3).toDF("foo").write.parquet(new Path(basePath, "foo=1").toString)
spark.range(0, 3).toDF("foo").write.parquet(new Path(basePath, "foo=a").toString)
spark.read.parquet(basePath).show()
}
+---+
|foo|
+---+
| 1|
| 1|
| a|
| a|
| 1|
| a|
+---+
```
This patch added code to print a warning when the duplication found.
## How was this patch tested?
Manually checked.
Author: Takeshi Yamamuro <yamamuro@apache.org>
Closes#18375 from maropu/SPARK-21144-3.
## What changes were proposed in this pull request?
Currently the validation of sampling fraction in dataset is incomplete.
As an improvement, validate sampling fraction in logical operator level:
1) if with replacement: fraction should be nonnegative
2) else: fraction should be on interval [0, 1]
Also add test cases for the validation.
## How was this patch tested?
integration tests
gatorsmile cloud-fan
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Wang Gengliang <ltnwgl@gmail.com>
Closes#18387 from gengliangwang/sample_ratio_validate.
## What changes were proposed in this pull request?
Integrate Apache Arrow with Spark to increase performance of `DataFrame.toPandas`. This has been done by using Arrow to convert data partitions on the executor JVM to Arrow payload byte arrays where they are then served to the Python process. The Python DataFrame can then collect the Arrow payloads where they are combined and converted to a Pandas DataFrame. All non-complex data types are currently supported, otherwise an `UnsupportedOperation` exception is thrown.
Additions to Spark include a Scala package private method `Dataset.toArrowPayloadBytes` that will convert data partitions in the executor JVM to `ArrowPayload`s as byte arrays so they can be easily served. A package private class/object `ArrowConverters` that provide data type mappings and conversion routines. In Python, a public method `DataFrame.collectAsArrow` is added to collect Arrow payloads and an optional flag in `toPandas(useArrow=False)` to enable using Arrow (uses the old conversion by default).
## How was this patch tested?
Added a new test suite `ArrowConvertersSuite` that will run tests on conversion of Datasets to Arrow payloads for supported types. The suite will generate a Dataset and matching Arrow JSON data, then the dataset is converted to an Arrow payload and finally validated against the JSON data. This will ensure that the schema and data has been converted correctly.
Added PySpark tests to verify the `toPandas` method is producing equal DataFrames with and without pyarrow. A roundtrip test to ensure the pandas DataFrame produced by pyspark is equal to a one made directly with pandas.
Author: Bryan Cutler <cutlerb@gmail.com>
Author: Li Jin <ice.xelloss@gmail.com>
Author: Li Jin <li.jin@twosigma.com>
Author: Wes McKinney <wes.mckinney@twosigma.com>
Closes#15821 from BryanCutler/wip-toPandas_with_arrow-SPARK-13534.
## What changes were proposed in this pull request?
Currently we have several tens of test sqls in catalyst will fail at `SimpleAnalyzer.checkAnalysis`, we should make sure they are valid.
This PR makes the following changes:
1. Apply `checkAnalysis` on plans that tests `Optimizer` rules, but don't require the testcases for `Parser`/`Analyzer` pass `checkAnalysis`;
2. Fix testcases for `Optimizer` that would have fall.
## How was this patch tested?
Apply `SimpleAnalyzer.checkAnalysis` on plans in `PlanTest.comparePlans`, update invalid test cases.
Author: Xingbo Jiang <xingbo.jiang@databricks.com>
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15417 from jiangxb1987/cptest.
## What changes were proposed in this pull request?
This PR aims to clarify some outdated comments that i found at **spark-catalyst** and **spark-sql** pom files. Maven bug still happening and in order to track it I have updated the issue link and also the status of the issue.
Author: Marcos P <mpenate@stratio.com>
Closes#18374 from mpenate/fix/mng-3559-comment.
## What changes were proposed in this pull request?
QueryPlanConstraints should be part of LogicalPlan, rather than QueryPlan, since the constraint framework is only used for query plan rewriting and not for physical planning.
## How was this patch tested?
Should be covered by existing tests, since it is a simple refactoring.
Author: Reynold Xin <rxin@databricks.com>
Closes#18310 from rxin/SPARK-21103.
## What changes were proposed in this pull request?
Fix some typo of the document.
## How was this patch tested?
Existing tests.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Xianyang Liu <xianyang.liu@intel.com>
Closes#18350 from ConeyLiu/fixtypo.
## What changes were proposed in this pull request?
This PR cleans up a few Java linter errors for Apache Spark 2.2 release.
## How was this patch tested?
```bash
$ dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.
```
We can check the result at Travis CI, [here](https://travis-ci.org/dongjoon-hyun/spark/builds/244297894).
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#18345 from dongjoon-hyun/fix_lint_java_2.
### What changes were proposed in this pull request?
We should not silently ignore `DISTINCT` when they are not supported in the function arguments. This PR is to block these cases and issue the error messages.
### How was this patch tested?
Added test cases for both regular functions and window functions
Author: Xiao Li <gatorsmile@gmail.com>
Closes#18340 from gatorsmile/firstCount.
## What changes were proposed in this pull request?
Built-in SQL Function UnaryMinus/UnaryPositive support string type, if it's string type, convert it to double type, after this PR:
```sql
spark-sql> select positive('-1.11'), negative('-1.11');
-1.11 1.11
spark-sql>
```
## How was this patch tested?
unit tests
Author: Yuming Wang <wgyumg@gmail.com>
Closes#18173 from wangyum/SPARK-20948.
## What changes were proposed in this pull request?
This PR adds built-in SQL function `BIT_LENGTH()`, `CHAR_LENGTH()`, and `OCTET_LENGTH()` functions.
`BIT_LENGTH()` returns the bit length of the given string or binary expression.
`CHAR_LENGTH()` returns the length of the given string or binary expression. (i.e. equal to `LENGTH()`)
`OCTET_LENGTH()` returns the byte length of the given string or binary expression.
## How was this patch tested?
Added new test suites for these three functions
Author: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Closes#18046 from kiszk/SPARK-20749.
## What changes were proposed in this pull request?
This pull-request exclusively includes the class splitting feature described in #16648. When code for a given class would grow beyond 1600k bytes, a private, nested sub-class is generated into which subsequent functions are inlined. Additional sub-classes are generated as the code threshold is met subsequent times. This code includes 3 changes:
1. Includes helper maps, lists, and functions for keeping track of sub-classes during code generation (included in the `CodeGenerator` class). These helper functions allow nested classes and split functions to be initialized/declared/inlined to the appropriate locations in the various projection classes.
2. Changes `addNewFunction` to return a string to support instances where a split function is inlined to a nested class and not the outer class (and so must be invoked using the class-qualified name). Uses of `addNewFunction` throughout the codebase are modified so that the returned name is properly used.
3. Removes instances of the `this` keyword when used on data inside generated classes. All state declared in the outer class is by default global and accessible to the nested classes. However, if a reference to global state in a nested class is prepended with the `this` keyword, it would attempt to reference state belonging to the nested class (which would not exist), rather than the correct variable belonging to the outer class.
## How was this patch tested?
Added a test case to the `GeneratedProjectionSuite` that increases the number of columns tested in various projections to a threshold that would previously have triggered a `JaninoRuntimeException` for the Constant Pool.
Note: This PR does not address the second Constant Pool issue with code generation (also mentioned in #16648): excess global mutable state. A second PR may be opened to resolve that issue.
Author: ALeksander Eskilson <alek.eskilson@cerner.com>
Closes#18075 from bdrillard/class_splitting_only.
